// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stddef.h>

#include "base/numerics/safe_conversions.h"
#include "base/optional.h"
#include "media/filters/h264_parser.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/size.h"

static volatile size_t volatile_sink;

// Entry point for LibFuzzer.
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size)
{
    if (!size)
        return 0;

    media::H264Parser parser;
    parser.SetStream(data, base::checked_cast<off_t>(size));

    // Parse until the end of stream/unsupported stream/error in stream is
    // found.
    while (true) {
        media::H264NALU nalu;
        media::H264Parser::Result res = parser.AdvanceToNextNALU(&nalu);
        if (res != media::H264Parser::kOk)
            break;

        switch (nalu.nal_unit_type) {
        case media::H264NALU::kIDRSlice:
        case media::H264NALU::kNonIDRSlice: {
            media::H264SliceHeader shdr;
            res = parser.ParseSliceHeader(nalu, &shdr);
            break;
        }

        case media::H264NALU::kSPS: {
            int id;
            res = parser.ParseSPS(&id);
            if (res != media::H264Parser::kOk)
                break;
            const media::H264SPS* sps = parser.GetSPS(id);
            if (!sps)
                break;
            // Also test the SPS helper methods. We make sure that the results are
            // used so that the calls are not optimized away.
            base::Optional<gfx::Size> coded_size = sps->GetCodedSize();
            volatile_sink = coded_size.value_or(gfx::Size()).ToString().length();
            base::Optional<gfx::Rect> visible_rect = sps->GetVisibleRect();
            volatile_sink = visible_rect.value_or(gfx::Rect()).ToString().length();
            break;
        }

        case media::H264NALU::kPPS: {
            int id;
            res = parser.ParsePPS(&id);
            break;
        }

        case media::H264NALU::kSEIMessage: {
            media::H264SEIMessage sei_msg;
            res = parser.ParseSEI(&sei_msg);
            break;
        }

        default:
            // Skip any other NALU.
            break;
        }
        if (res != media::H264Parser::kOk)
            break;
    }

    return 0;
}
